Graphics.UI.Gtk.ActionMenuToolbar.UIManager

Constructing menus and toolbars from an XML description

• Module available since Gtk+ version 2.4

Detail

A UIManager constructs a user interface (menus and toolbars) from one or more UI definitions, which reference actions from one or more action groups.

UI Definitions

The UI definitions are specified in an XML format which can be roughly described by the following DTD.

<!ELEMENT ui (menubar|toolbar|popup|accelerator)* >
<!ELEMENT menubar (menuitem|separator|placeholder|menu)* >
<!ELEMENT menu (menuitem|separator|placeholder|menu)* >
<!ELEMENT popup (menuitem|separator|placeholder|menu)* >
<!ELEMENT toolbar (toolitem|separator|placeholder)* >
<!ELEMENT placeholder (menuitem|toolitem|separator|placeholder|menu)* >
<!ELEMENT menuitem EMPTY >
<!ELEMENT toolitem EMPTY >
<!ELEMENT separator EMPTY >
<!ELEMENT accelerator EMPTY >
<!ATTLIST menubar name #IMPLIED
action #IMPLIED >
<!ATTLIST toolbar name #IMPLIED
action #IMPLIED >
<!ATTLIST popup name #IMPLIED
action #IMPLIED >
<!ATTLIST placeholder name #IMPLIED
action #IMPLIED
expand (true|false) #IMPLIED >
<!ATTLIST separator name #IMPLIED
action #IMPLIED >
<!ATTLIST menu name #IMPLIED
action #REQUIRED
position (top|bot) #IMPLIED >
<!ATTLIST menuitem name #IMPLIED
action #REQUIRED
position (top|bot) #IMPLIED >
<!ATTLIST toolitem name #IMPLIED
action #REQUIRED
position (top|bot) #IMPLIED >
<!ATTLIST accelerator name #IMPLIED
action #REQUIRED >

There are some additional restrictions beyond those specified in the DTD, e.g. every toolitem must have a toolbar in its anchestry and every menuitem must have a menubar or popup in its anchestry. Since a GMarkup parser is used to parse the UI description, it must not only be valid XML, but valid GMarkup.

If a name is not specified, it defaults to the action. If an action is not specified either, the element name is used. The name and action attributes must not contain '/' characters after parsing (since that would mess up path lookup) and must be usable as XML attributes when enclosed in doublequotes, thus they must not '"' characters or references to the " entity.

A UI definition

<ui>
<menubar>
<menu name="FileMenu" action="FileMenuAction">
<menuitem name="New" action="New2Action" />
<placeholder name="FileMenuAdditions" />
</menu>
<menu name="JustifyMenu" action="JustifyMenuAction">
<menuitem name="Left" action="justify-left"/>
<menuitem name="Centre" action="justify-center"/>
<menuitem name="Right" action="justify-right"/>
<menuitem name="Fill" action="justify-fill"/>
</menu>
</menubar>
<toolbar action="toolbar1">
<placeholder name="JustifyToolItems">
<separator/>
<toolitem name="Left" action="justify-left"/>
<toolitem name="Centre" action="justify-center"/>
<toolitem name="Right" action="justify-right"/>
<toolitem name="Fill" action="justify-fill"/>
<separator/>
</placeholder>
</toolbar>
</ui>

UI Merging

The most remarkable feature of UIManager is that it can overlay a set of menuitems and toolitems over another one, and demerge them later.

Merging is done based on the names of the XML elements. Each element is identified by a path which consists of the names of its anchestors, separated by slashes. For example, the menuitem named "Left" in the example above has the path /ui/menubar/JustifyMenu/Left and the toolitem with the same name has path /ui/toolbar1/JustifyToolItems/Left.

Accelerators

Every action has an accelerator path. Accelerators are installed together with menuitem proxies, but they can also be explicitly added with <accelerator> elements in the UI definition. This makes it possible to have accelerators for actions even if they have no visible proxies.

Smart Separators

The separators created by UIManager are "smart", i.e. they do not show up in the UI unless they end up between two visible menu or tool items. Separators which are located at the very beginning or end of the menu or toolbar containing them, or multiple separators next to each other, are hidden. This is a useful feature, since the merging of UI elements from multiple sources can make it hard or impossible to determine in advance whether a separator will end up in such an unfortunate position.

For separators in toolbars, you can set expand="true" to turn them from a small, visible separator to an expanding, invisible one. Toolitems following an expanding separator are effectively right-aligned.

Empty Menus

Submenus pose similar problems to separators inconnection with merging. It is impossible to know in advance whether they will end up empty after merging. UIManager offers two ways to treat empty submenus:

• make them disappear by hiding the menu item they're attached to
• add an insensitive "Empty" item

The behaviour is chosen based on the "hide_if_empty" property of the action to which the submenu is associated.

Class Hierarchy

| GObject
| +----UIManager

Types

data UIManager

Instances

Eq UIManager

Ord UIManager

GObjectClass UIManager

UIManagerClass UIManager

class GObjectClass o => UIManagerClass o

Instances

UIManagerClass UIManager

castToUIManager :: GObjectClass obj => obj -> UIManager

gTypeUIManager :: GType

toUIManager :: UIManagerClass o => o -> UIManager

data UIManagerItemType

These enumeration values are used by uiManagerAddUi to determine what UI element to create.

Constructors

UiManagerAuto

UiManagerMenubar

UiManagerMenu

UiManagerToolbar

UiManagerPlaceholder

UiManagerPopup

UiManagerMenuitem

UiManagerToolitem

UiManagerSeparator

UiManagerAccelerator

UiManagerPopupWithAccels

Instances

Bounded UIManagerItemType

Enum UIManagerItemType

Flags UIManagerItemType

data MergeId

Constructors

uiManagerNew :: IO UIManager

Creates a new ui manager object.

Methods

uiManagerSetAddTearoffs

Arguments

:: UIManager

-> Bool

addTearoffs - whether tearoff menu items are added

-> IO ()

Sets the "add_tearoffs" property, which controls whether menus generated by this UIManager will have tearoff menu items.

Note that this only affects regular menus. Generated popup menus never have tearoff menu items.

uiManagerGetAddTearoffs

Arguments

:: UIManager

-> IO Bool

returns whether tearoff menu items are added

Returns whether menus generated by this UIManager will have tearoff menu items.

uiManagerInsertActionGroup

Arguments

:: UIManager

-> ActionGroup

actionGroup - the action group to be inserted

-> Int

pos - the position at which the group will be inserted.

-> IO ()

Inserts an action group into the list of action groups associated with self. Actions in earlier groups hide actions with the same name in later groups.

uiManagerRemoveActionGroup

Arguments

:: UIManager

-> ActionGroup

actionGroup - the action group to be removed

-> IO ()

Removes an action group from the list of action groups associated with self.

uiManagerGetActionGroups :: UIManager -> IO [ActionGroup]

Returns the list of action groups associated with the UI manager.

uiManagerGetAccelGroup

Arguments

:: UIManager

-> IO AccelGroup

returns the AccelGroup.

Returns the AccelGroup associated with self.

uiManagerGetWidget

Arguments

:: GlibString string

=> UIManager

-> string

path - a path

-> IO (Maybe Widget)

returns the widget found by following the path, or Nothing if no widget was found.

Looks up a widget by following a path. The path consists of the names specified in the XML description of the UI. separated by '/'. Elements which don't have a name or action attribute in the XML (e.g. <popup>) can be addressed by their XML element name (e.g. "popup"). The root element ("/ui") can be omitted in the path.

Note that the widget found by following a path that ends in a <menu> element is the menuitem to which the menu is attached, not the menu itself.

uiManagerGetToplevels

Arguments

:: UIManager

-> [UIManagerItemType]

types - specifies the types of toplevel widgets to include. Allowed types are UiManagerMenubar, UiManagerToolbar and UiManagerPopup.

-> IO [Widget]

returns a list of all toplevel widgets of the requested types.

Obtains a list of all toplevel widgets of the requested types.

uiManagerGetAction

Arguments

:: GlibString string

=> UIManager

-> string

path - a path

-> IO (Maybe Action)

returns the action whose proxy widget is found by following the path, or Nothing if no widget was found.

Looks up an action by following a path. See uiManagerGetWidget for more information about paths.

uiManagerAddUiFromString

Arguments

:: GlibString string

=> UIManager

-> string

buffer - the string to parse

-> IO MergeId

returns The merge id for the merged UI. The merge id can be used to unmerge the UI with uiManagerRemoveUi.

Parses a string containing a UI definition and merges it with the current contents of self. An enclosing <ui> element is added if it is missing.

If a parse error occurres, an exception is thrown.

uiManagerAddUiFromFile

Arguments

:: GlibString string

=> UIManager

-> string

filename - the name of the file to parse

-> IO MergeId

returns The merge id for the merged UI. The merge id can be used to unmerge the UI with uiManagerRemoveUi.

Parses a file containing a UI definition and merges it with the current contents of self.

If a parse or IO error occurres, an exception is thrown.

uiManagerNewMergeId :: UIManager -> IO MergeId

Returns an unused merge id, suitable for use with uiManagerAddUi.

uiManagerAddUi

Arguments

:: GlibString string

=> UIManager

-> MergeId

mergeId - the merge id for the merged UI, see uiManagerNewMergeId

-> string

path - a path

-> string

name - the name for the added UI element

-> Maybe string

action - the name of the action to be proxied, or Nothing to add a separator

-> [UIManagerItemType]

type - the type of UI element to add.

-> Bool

top - if True, the UI element is added before its siblings, otherwise it is added after its siblings.

-> IO ()

Adds a UI element to the current contents of self.

If type is UiManagerAuto, Gtk+ inserts a menuitem, toolitem or separator if such an element can be inserted at the place determined by path. Otherwise type must indicate an element that can be inserted at the place determined by path.

If path points to a menuitem or toolitem, the new element will be inserted before or after this item, depending on top.

uiManagerRemoveUi

Arguments

:: UIManager

-> MergeId

mergeId - a merge id as returned by uiManagerAddUiFromString

-> IO ()

Unmerges the part of the UI manager's content identified by mergeId.

uiManagerGetUi

Arguments

:: GlibString string

=> UIManager

-> IO string

returns string containing an XML representation of the merged UI.

Creates a UI definition of the merged UI.

uiManagerEnsureUpdate :: UIManager -> IO ()

Makes sure that all pending updates to the UI have been completed.

This may occasionally be necessary, since UIManager updates the UI in an idle function. A typical example where this function is useful is to enforce that the menubar and toolbar have been added to the main window before showing it:

do
containerAdd window vbox
onAddWidget merge (addWidget vbox)
uiManagerAddUiFromFile merge "my-menus"
uiManagerAddUiFromFile merge "my-toolbars"
uiManagerEnsureUpdate merge
widgetShow window

Attributes

uiManagerAddTearoffs :: Attr UIManager Bool

The "add-tearoffs" property controls whether generated menus have tearoff menu items.

Note that this only affects regular menus. Generated popup menus never have tearoff menu items.

Default value: False

uiManagerUi :: GlibString string => ReadAttr UIManager string

An XML string describing the merged UI.

Default value: "<ui>\n</ui>\n"

Signals

addWidget :: UIManagerClass self => Signal self (Widget -> IO ())

The add_widget signal is emitted for each generated menubar and toolbar. It is not emitted for generated popup menus, which can be obtained by uiManagerGetWidget.

actionsChanged :: UIManagerClass self => Signal self (IO ())

The "actions-changed" signal is emitted whenever the set of actions changes.

Deprecated

onAddWidget :: UIManagerClass self => self -> (Widget -> IO ()) -> IO (ConnectId self)

The add_widget signal is emitted for each generated menubar and toolbar. It is not emitted for generated popup menus, which can be obtained by uiManagerGetWidget.

afterAddWidget :: UIManagerClass self => self -> (Widget -> IO ()) -> IO (ConnectId self)

The add_widget signal is emitted for each generated menubar and toolbar. It is not emitted for generated popup menus, which can be obtained by uiManagerGetWidget.

onActionsChanged :: UIManagerClass self => self -> IO () -> IO (ConnectId self)

The "actions-changed" signal is emitted whenever the set of actions changes.

afterActionsChanged :: UIManagerClass self => self -> IO () -> IO (ConnectId self)

The "actions-changed" signal is emitted whenever the set of actions changes.

onConnectProxy :: UIManagerClass self => self -> (Action -> Widget -> IO ()) -> IO (ConnectId self)

The connect_proxy signal is emitted after connecting a proxy to an action in the group.

This is intended for simple customizations for which a custom action class would be too clumsy, e.g. showing tooltips for menuitems in the statusbar.

afterConnectProxy :: UIManagerClass self => self -> (Action -> Widget -> IO ()) -> IO (ConnectId self)

The connect_proxy signal is emitted after connecting a proxy to an action in the group.

This is intended for simple customizations for which a custom action class would be too clumsy, e.g. showing tooltips for menuitems in the statusbar.

onDisconnectProxy :: UIManagerClass self => self -> (Action -> Widget -> IO ()) -> IO (ConnectId self)

The disconnect_proxy signal is emitted after disconnecting a proxy from an action in the group.

afterDisconnectProxy :: UIManagerClass self => self -> (Action -> Widget -> IO ()) -> IO (ConnectId self)

The disconnect_proxy signal is emitted after disconnecting a proxy from an action in the group.

onPreActivate :: UIManagerClass self => self -> (Action -> IO ()) -> IO (ConnectId self)

The pre_activate signal is emitted just before the action is activated.

This is intended for applications to get notification just before any action is activated.

afterPreActivate :: UIManagerClass self => self -> (Action -> IO ()) -> IO (ConnectId self)

The pre_activate signal is emitted just before the action is activated.

This is intended for applications to get notification just before any action is activated.

onPostActivate :: UIManagerClass self => self -> (Action -> IO ()) -> IO (ConnectId self)

The post_activate signal is emitted just after the action is activated.

This is intended for applications to get notification just after any action is activated.

afterPostActivate :: UIManagerClass self => self -> (Action -> IO ()) -> IO (ConnectId self)

The post_activate signal is emitted just after the action is activated.

This is intended for applications to get notification just after any action is activated.